Air pollution has a huge impact on health. Studies have pointed out that exhaust gas, soot and dust emitted from fuel combustion during the production process in various types of factories and thermal power plants, the exhaust gas emitted by vehicles such as automobiles, motorbikes, airplanes, trains and ships, and the fumes produced by various human activities are the causes of current air pollution.
Take the vehicle as an example, during the operation of the vehicle engine, different forms of fuel release heat energy via internal combustion in the cylinder, thereby generating transmission power. However, in the combustion process, the generated exhaust gas contains harmful pollutants such as nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons (HCs) and particulate matter (PM). Therefore, the harmful pollutants not only form photochemical smog, but also exacerbate the deterioration of the greenhouse effect and causes negative effects such as acid rain, destroying the ecological environment and also harming human health.
Therefore, many countries have already set strict exhaust emission standards to control and reduce the emission of harmful gases. At the same time, they encourage companies to manufacture, develop, and introduce products that use the latest pollution control technologies. For example, the U.S. Pat. No. 5,401,372 discloses an “Electrochemical catalytic reduction cell for the reduction of NOx in an O2-containing exhaust emission”, which catalyzes the conversion of nitrogen oxides into nitrogen with vanadium pentoxide (V2O5) catalyst under an electrochemical catalyst reduction reaction. However, the device must be additionally supplied with a power source to operate an electrochemical cell in the device.
In order to solve the above drawbacks, the inventor of the present application proposed the U.S. Pat. No. 9,028,764B2, it discloses an “Electro-Catalytic Honeycomb for Exhaust Emissions Control” including an electro-catalytic honeycomb for controlling exhaust emissions. The electro-catalytic honeycomb is used for purifying nitrogen oxides, carbon monoxide, hydrocarbons and particulate matter in exhaust gas, wherein the nitrogen oxides are decomposed into nitrogen and oxygen, and the carbon monoxide, the hydrocarbons, and the particulate matter are oxidized into carbon dioxide and water. The electro-catalyst honeycomb for exhaust emissions control purifies a variety of pollutants without consuming additional energy and reducing gases.
Since the above-mentioned electro-catalytic honeycomb for exhaust emissions control is manufactured in a way that both the cathode and the anode are exposed to the open space, it is difficult to reduce the anode to form a reducing environment, and there is still room for improvement. Therefore, the inventor of the present invention and one other inventor proposed the Taiwan Patent No. I572406 “An Electro-catalytic Honeycomb for Exhaust Emissions Control and Manufacturing Method Thereof”, which provides a method for improvement by using the sealing body to separate the cathode and the anode before reducing the anode so that subsequent steps are performed and the anode is sufficiently reduced.
However, the above method still has the problem of difficulty in the manufacturing process, which is because it takes a lot of time to form a sufficient reducing environment by sufficiently reducing a metal oxide in the anode to become a metal. Therefore, the production time is longer, and problem with yield rate may occur in the electro-catalytic honeycomb depending on the degree of incomplete reduction or uneven reduction.